I don't know how hydraulic fluid would stay in the socket. My father has a 1985 300D and the Haynes manual for his car says to apply white lithium grease with a brush. The only lithium grease I had was in a spray can, so I also used heavy grease. I popped off the socket and put a good amount in each socket and popped them back together. Then I wiped off the excess. This seemed to quite down the linkage a bit.